Improvement in air-compressors



UNITED STATES PATENT OEEreEL GEORGE wEsr'rNeHoUsE, JE.,'0E PIrrsBUEG, .PENNSYINANIA IMPROVEMENT IN AIR-COMPRESSORS.

Specification forming part of Letters Patent No. [73,835, dated February 22, 1876; application filed December 250, 1875.

To all whom it may concern.:

Beit known that I, GEORGE WEs'rrNeHoUsE, Jr., of Pittsburg, county of Allegheny, State of Pennsylvania, havein vented or discovered a new and useful Improvementin Air-Compress ors 5 and I do herebydcclarethe following to be a full, clear, concise, and exact description thereof, reference being had to the accompanying drawing, making a part of this specification, which represents my improvement in A and A represent two independent steam engines 4of any suitable known construction. As shown, they are 'of cylindrical form, each `with a steam-supply and exhaust port, a a.

' The internal construction of such engines is not shown, as it constitutes no part of the present invention.

B represents the rst air-pump in the series, and D the second. rEhe piston-stem b of the first engine in the series constitutes also the piston-stem of the first pump B, so as to actuate its piston b. The same piston and stemconnection d d is also employed with the second and each succeeding engine and pump in the series. R R are two receivers, which alternate with the pumps inthe line of the passage of air, the pump B compressing the air into It, and the pump D taking the air thus compressed from R and further compressing it into ligand so on through a succession of pumps and receivers to any desired extent. The pump B takes in air from without, by any s suitable pipe or port, p, alternately atits opposite ends, through check-valves c c', and forces or compresses the same, by a like alternate action, through check-valves e e', into the receiver R, the closed check-valve in either case preventing escape or back pressure. By a like alternate action the .pump D takes air, as

thus compressed, from the receiverR through check-valves i i', and compresses it at -a still higher or greater degree of compression or density, through check-valves o o', into a receiver, B. From this receiver the air, thus compressed, istaken by any suitable pipeconnection to the place of use, or, if further compression is desired, the operation is repeated by like'l apparatus, till, in thelast receiver of the series, the desired working pressure is attained.

As each successive pump in the series is required to add to the degree ot' compression previously attained, and also as the bulk of the air` to be compressed is lessened at each successive stage of the operation, I make the successive pumps B D, Snc., through the se ries of a gradually-reduced area in cross-section'from one to the next, andapportion them all in relation to-each other, so that, with any given steam-pressure, such as is within the limits of ordinary steam-engine machinery, each successive pump in the series shall be capable ot' adding to the degree of density ot' compression previously attained, and also, so that the amount of work to be done by each, with reference to the finalI density desired, shall be properly distributed between the several pumps.

The rules governing this apportionment will come within the knowledge ofthe skilled mechanic, but I believe it best, having xed the power required for the last compression and the area of the piston, which, with the power employed, will do the work, to double the piston area of each preceding pump. Thus the enginepistons having each an area of eight square inches, the tirst pump-piston 'in the series may be made with an area lof sixteen squareinches, the second with eight, the third with four, and so on. But these proportions may be varied from to a considerable extent without departing from the scope of the invention.

As the rapidity ofthe motion of the pumps lwillvary somewhat with the resistance niet in compression of the air, it follows thatif the air be usedrapidly from the last receiver of -the series,the resistance to the action of the last pump will be correspondingly lessened, and such pump will then move more rapidly to supply the loss. This will result in the lowering of the air-pressure in the previous receiver, and hence will lessen the resistance tothe motion of the previous pump, and cause it to move more rapidly, and so on backwardly through lhe series, and as the pressure is restored the increased resistance will tend to reduce the speed of the pumps. Hence the action of the apparatus will automatically adjust itself to the requirements of the Work.

Each pump-piston, instead of being connected with the engine-pistons, may be operated independently of each or all the other pstons by any suitable crank or other motion, such as is employed in converting 'a rotary into a reciprocating motion, the power applied to operate each pump remaining, however, the same, or nearly so.

my hand.

GEO. WESTINGHOUSE, JR.

Witnesses:

JAMES M. CHRISTY,

GEORGE H. CHRISTY. 

